Expansion cards are widely used throughout the computer industry, including computers such as high-end and mid-range servers. An expansion card can be inserted in a card connector on a motherboard to provide additional computer functionality. Specifically, an expansion card has contact pads, and a card connector has a receiving slot with connector pins disposed adjacent to sidewalls of the receiving slot. Thus, connector pins can connect to contact pads after an expansion card is inserted in the receiving slot.
Furthermore, computers are often packaged and shipped to customer locations after expansion cards are inserted in receiving slots of card connectors. However, computers with expansion cards inserted in receiving slots are frequently subjected to shocks and vibrations during shipment of the computers and computer components. For example, computers can be subjected to shocks and vibrations while handlers are loading the computers on or off a vehicle, or are transporting the computers in a vehicle over a rough terrain. The shocks and vibrations can cause wearing and damage to interface material that is on connector pins and contact pads. Connector pins and contact pads are copper, and both connector pins and contact pads are coated with interface material that can include, but is not limited to, gold and nickel. Thus, the aggregate shock and vibrations during shipment can cause the gold and even the nickel interface material to completely wear away, leaving the copper of the connector pins and the copper of the contact pads exposed and in direct contact with each other. The wearing away of interface material can be detrimental to the reliability of an electrical connection between connector pins and contact pads. Specifically, the wearing away of interface material can lead to a weak electrical connection between connector pins and contact pads, which can cause an expansion card to operate incorrectly or completely fail because of the weak electrical connection. The challenge of providing a card connector and an expansion card that mitigates the wearing away of the interface material and provides a reliable electrical connection between connector pins and contact pads continues to persist.